homozygous bacteria

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12 Week Benchmark Study Guide
Organisms
Characteristics of Living Things (Biology: the study of living things)
Homeostasis – maintaining a balanced internal conditions
Organization - Cells  Tissue  Organs  Organ systems  Organism (living thing)
Growth - gets bigger or adds cells or matures
Reproduce - asexual or sexual; making more of one’s species
Energy - organisms must make or obtain energy (food) – ‘metabolism’
Cells - all living things are made of cells or at least one cell (unicellular)
Respond - responding to stimuli such as temperature, pH, needs such as food,….etc.
Viruses - They are NOT alive. They do not meet all of the HOGRECR
- Antibiotics do not kill or help a viral infection such as the common cold or influenza.
- Viruses are not plants, animals, or bacteria, but they are parasites of the living kingdoms.
Protein Capsid
- contains the nucleic acid (DNA)
Classification
Taxonomy - The study of classification!
Aristotle– grouped things by where they lived (environment
Linnaeus – developed our classification system used now...
uses 2 Latin words – Binomial Nomenclature
7 levels of Classification
Kingdoms
6 Kingdoms: Archaebacteria, Eubacteria, Protists, Fungi, Plantae, Animalia
Phylum
Scientific Name -the Genus (capitalized) and Species.
Large
Class
order
to
family
Genus
small
Species Example : Homo sapiens or Homo sapiens
Unicellular
Multicellular
Eubacteria
Archaebacteria
Most Protists
Autotrophic
Plants
plant-like Protists
Some chlorophyll containing Bacteria
Fungi
Plants
Animals
Algae (Protist)
Heterotrophic
animal-like Protists
fungi-like Protists
Bacteria
Fungi (by absorption)
Animals (by ingestion)
Producer
Consumer
Plants
algae-like Protists
Some chlorophyll containing Bacteria
Decomposer
animal-like Protists
Animals
Fungi-like Protists
Fungi
Bacteria
GENETICS
Mendelian Genetics and Meiosis/Mitosis
Asexual Reproduction
Sexual Reproduction
Binary Fission – bacteria
Cloning – cells
Budding – like the hydras
Vegetative Propagation - Runners/shoots – like some plants
Conjugation of unicellular organism
External fertilization – like frogs and fish
Internal fertilization – like mammals
Alternation of Generations
Fungi – going from asexual producing spores to sexual union of specialized cells
Moss plants – sporophytes that produce spores to gameteophytes making sperm and egg
Mitosis : 1 body (somatic) cell divides to make 2 new cells
Diploid (2n) --- Diploid (2n)
Interphase:
Prophase:
Resting
(from nuclear division)
DNA replicates
chromosomes
become visible
Metaphase:
chromosome line-up
along the middle
Anaphase:
Telophase:
chrosmosomes
begin to separate (pull apart)
chromosomes have
separated; cell pinches in
or develops a cell plate
Cytokinesis – when animal cells pinch in dividing the cytoplasm in the last stage of mitosis
Meiosis : cell division to create gametes (sex cells: sperm & egg)
-diploid (2n) -- haploid (1n)
-1 cell divides to make 4 haploid cells
*** Crossing over during Prophase I allows more genetic variation!!!
Prophase I
Metaphase I
(crossing over of tetrads)
(Homologous Pairs)
Prophase II
Metaphase II
(chromosomes line up single)
Anaphase I
(homologous pairs separate)
Anaphase II
(chromatids pull apart)
Telophase I
(2 haploid cells)
Telophase II
(4 new gamete haploid cells)
When an egg is fertilized by one sperm
it becomes a zygote.
Zygotes go through Mitosis to grow and develop
into a blastula  gastrula  embryo.
fertilization
mitosis
Karyotype – picture of a person’s homologous chromosomes
ex chromosomes:
XX – female
XY – male
This karyotype is of an individual with Down Syndrome or Trisomy 21- resulting from
nondisjunction
‘The Father
of Genetics’ - Gregor Mendel
An Austrian monk that grew garden peas.
He observed and recorded the factors for flower color, pea color,
and pea texture for several generations.
Three conclusions/laws:
1 - Dominant & Recessive traits
2 – Independent Assortment
3 – Segregation of alleles (during gamete formation)
Humans have 46 (2n) chromosomes in each somatic cell.
- There are 23 Homologous Pairs for each chromosome.
- There are 2 sex chromosomes: XX female & XY male.
- Somatic cells (body cells) are coded for in the autosomes (22 pairs)
Humans have 23 (1n) chromosomes in each gamete.
Alleles – different forms of the same gene (eye colors)
Tetrads are formed in Meiosis - the Homologous pairs become
entangled in a process called synapsis. Crossing over can occur
during this time. (Prophase I)
(It is the Homologous pair that is pulled apart during Anaphase I)
Genotype - the traits (alleles for the trait) are represented by letters (Tt, Aa, BB, dd)
Genotypic ratio is reported in the following order - Homozygous Dominant : Heterozygous: Homozygous Recessive
Phenotype – the appearance of a trait; what the offspring looks like (Tall : short, curly hair : straight hair)
Phenotypic ratio is reported from the Dominant to the Recessive trait showing.
The physical appearance of
Homozygous Dominant & Heterozygous
The physical appearance of
: Homozygous Recessive
Punnett Square – device showing probability of traits
Parental alleles -gametes (genotype) goes on the outside of the box
H
h
H
HH
Hh
h
Hh
hh
Dominant (capital letters) trait will appear (covers any recessive traits)
Recessive (lower case letters) – trait is masked or covered by the dominant.
Recessive traits only show up it it is homozygous recessive (lower case)
1 : 2 : 1 Genotype ratio
3 : 1 Phenotype ratio
show trait : don’t show trait
HD: HE : HR
Homozygous Dominant - both capital letters/dominant for genotype (TT , AA, BB)
Heterozygous - One letter is capital/dominant & one is small/recessive (Tt, Aa, Bb)
Homozygous Recessive – both letters are small/recessive (tt, aa, bb)
Pedigrees – graphic organizer showing family & trait occurrence by genotype (Some pedigrees show only phenotypes)
Males
Females
Homozygous for trait
heterozygous for trait
Genetic Conditions
Dominant genes
Polydactyly
Cataracts
Scoliosis
Recessive genes
Albinism
PKU
Cystic Fibrosis
Polygenic traits
skin color
hair color
height
Multiple alleles
Blood types
Extra Chromosome
Downs Syndrome
Missing Chromosome
Turner’s Syndrome
Sex-influenced
baldness
Sex-linked
Color blind
Hemophilia
Patterns of Inheritance
1. simple dominance (either dominant or recessive)
2. incomplete dominance (blend)
3. codominance (both show)
4. multiple alleles (more than one allele represents a trait - blood types)
5. sex-linked (carried on X – more common in males)
6. polygenic (more than one gene represents a trait)
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